Koolsville has been doing tattoos in Las Vegas since the mid-1980s and is the most honest about what it is — a high-volume walk-in shop built around bachelorette-weekend and Fremont-Street tourism, famous for its $10 and $20 specials. It has four locations, all of them within a few miles of Downtown.
It is not the place for a large custom piece. It is, pragmatically, the place where a lot of first tattoos happen in this city, and the shop has been doing that work long enough to have the sterilization and workflow dialed. Know what you are buying and you will be fine.